C-V2X outlines two types of scheduling schemes known as mode-3 and mode-4. The former one is a centralized scheme that harnesses cellular infrastructure to suitably distribute the sidelink subchannels among the vehicles in network coverage [1]}, [2]}, [3]}. Contrastingly, mode-4 has been engineered to operate autonomously and distributedly without network support. Thus, vehicles monitor the received power on each subchannel and select an appropriate one for their own usage. Exploiting an strategy of sensing and selection [4]}, [5]}, [6]}, [7]}, vehicles attempt to fulfill a two-fold objective: \((ii)\)  improve the likelihood of their own messages being received reliably and \((i)\)  not affect the conditions of subchannels being utilized by other vehicles. An indisputable advantage of mode-3 is that subchannels can be more efficiently utilized as eNodeBs can consolidate an humongous knowledge of all vehicles in coverage. Furthermore, due to coherent orchestration between eNodeBs, subchannel assignments free of conflicts can be attained [8]}. Nonetheless, signaling between vehicles and eNodeBs via uplink/downlink may pose a challenge in terms of latency exigencies. Conversely, in mode-4 due to absence of a central controller, latency owing to signaling and scheduling processing is nonexistent. On the downside, however, limited local knowledge at each vehicle may hinder the selection of a subchannel that is evenly fair for all vehicles in the system. As a consequence of uncoordinated strategies, several vehicles may compete over the same resources thus provoking collisions and leading to severe degradation of the packet reception ratio (PRR).
